Process for concentrating polymer latexes

Abstract

The invention concerns a process for concentrating polymer latexes, which can be separated into a latex phase and a serum phase in a separator with the aid of an auxiliary coalescing device.

1. A process for increasing the solids content of polymer latexes comprising the step of separating a latex dispersion into latex and serum in a separator by means of an auxiliary coalescing device, wherein the latex disoersion is mixed with a creaming agent comprising alginates or cellulose derivatives, and then introduced into the separator fitted with the auxiliary coalescing device, from which, a certain residence time, in which the latex dispersion can separate into two phases, the concentrated latex is drawn off. 
     
     
       2. A process according to  claim 1 , wherein the process is performed continuously. 
     
     
       3. A process for increasing the solids content of polymer latexes comprising the step of separating a latex dispersion into latex and serum in a separator by means of an auxiliary coalescing device, wherein the process is performed in a cascade arrangement in a cocurrent or countercurrent operation. 
     
     
       4. A process according to  claim 3 , wherein after separation in a first separator stage, an additional post-creaming of the thickened latex occurs in a second concentration stage. 
     
     
       5. A process according to  claim 1 , wherein said polymer latexes are (meth)acrylate latexes, polychloroprene latexes, polydichlorbutadiene-latexes, acrylonitrile-butadiene latexes, natural rubber latexes or latexes of copolymers thereof. 
     
     
       6. A process according to  claim 1 , wherein the creaming agent is an alginate or a cellulose derivative. 
     
     
       7. A process according to  claim 1 , wherein the auxiliary coalescing devices are knitted fabrics or microfiber beds in the form of candle filters. 
     
     
       8. A process according to  claim 7 , wherein the knitted fabrics or microfiber beds in the form of candle filters are made from staple glass fibers/stainless steel or polypropylene or polyester/stainless steel. 
     
     
       9. A process according to  claim 1 , wherein the residence time is from 15 to 60 minutes. 
     
     
       10. A process according to  claim 1 , wherein the process is performed in a cascade arrangement in a cocurrent or countercurrent operation. 
     
     
       11. A process according to  claim 10 , wherein after separation in a first separator stage, an additional post-creaming of the thickened latex occurs in a second concentration stage. 
     
     
       12. A process according to  claim 3 , wherein the latex dispersion is mixed with a creaming agent and then introduced into the separator fitted with the auxiliary coalescing device, from which, after a certain residence time, in which the latex dispersion can separate into two phases, the concentrated latex is drawn off. 
     
     
       13. A process according to  claim 12 , wherein the residence time is from 15 to 60 minutes. 
     
     
       14. A process according to  claim 3 , wherein said polymer latexes are (meth)acrylate latexes, polychloroprene latexes, polydichlorbutadiene-latexes, acrylonitrile-butadiene latexes, natural rubber latexes or latexes of copolymers thereof. 
     
     
       15. A process according to  claim 12 , wherein the creaming agents are alginates or cellulose derivatives. 
     
     
       16. A process according to  claim 3 , wherein the auxiliary coalescing devices are knitted fabrics or microfiber beds in the form of candle filters. 
     
     
       17. A process according to  claim 16 , wherein the knitted fabrics or microfiber beds in the form of candle filters are made from staple glass fibers/stainless steel or polypropylene or polyester/stainless steel.